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| Thread ID: 89665 | 2008-05-08 00:14:00 | To cross or not to cross? | ubergeek85 (131) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 667124 | 2008-05-08 00:14:00 | I'm in the process of connecting a computer to an embedded serial port in my DVD player (or at least I will be when my cables arrive). However, I've hit a bump. Do I connect the pad labeled RxD (on the DVD player PCB) to TxD (pin 3) or RxD (pin 2) on the PC's serial port (and vice versa). Wikipedia is just confusing me, so I though I'd ask here. Thanks. | ubergeek85 (131) | ||
| 667125 | 2008-05-08 03:52:00 | If you know the pin allocations at both ends, yes you need to connect RXD at one end to TXD at the other . That is, 2 to 3, 3 to 2, 5 to 5; (Even if you don't know the pin allocations you still have to do this, but you have to find out what the pins are . :D) The minimum connections you need are TXD to RXD (at least one way) and an earth wire (pin 5 both ends on DB9s) . The other nasties are the CTS, RTS, etc, status lines . IBMs PC "design" requires a few jumpers at the PC end in order for "standard" software to work . Wikipedia will probably show that for you . I saw a book once which had over a hundred pages of RS232 connecions used by various manufacturers . Standards are wonderful things . :crying |
Graham L (2) | ||
| 667126 | 2008-05-08 21:59:00 | Thanks. Yep, I do know which pins are what. The DVD player PCB has a 4-pin pad with nothing soldered to it which has the labels: 3.3v, RxD, TxD, GND, so it's pretty clear-cut. As for the other lines (CTS, RTS, etc), I'm using a USB to serial cable which automatically goes to 3.3v logic, not the 5v standard. Would those other pins matter? 'Cos I've seen designs for things like serial port mice, IR dongles, and whatnot, and they just use the rx and tx (as far as I can remember). We'll see... Thanks. | ubergeek85 (131) | ||
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